Update flow-parser (#18929)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: fisker <lionkay@gmail.com>

changelog_unreleased/flow/18929.md

@@ -0,0 +1,15 @@
+#### Support literal initializers and multiple declarations in `DeclareVariable` (#18929 by @fisker)
+
+<!-- prettier-ignore -->
+```flow
+// Input
+declare const x: string, y: number;
+declare const s = 'foo';
+
+// Prettier stable
+SyntaxError: Unexpected token `,`, expected the token `;` (1:24)
+
+// Prettier main
+declare const x: string, y: number;
+declare const s = "foo";
+```